Well, we'll agree to disgree on that one then.
A stud should never be torqued into a bottomed out hole.
Finger tight with a bit of loctite if you're using a locknut. (Although I don't think loctight works at high temperatures)
But as Pash has pointed out, these particular studs seem to be an interference fit, probably for that reason. But I will only nip the new ones into the forward head with some tefgel.
If the ones I have on the rear head had been put in properly, I wouldn't be having trouble with them now.
The stud isn't supposed to be part of the piece it's screwed into. That's not the point of a fastener. It's there to be under tension, (residual stress) and clamp the components together.
Studs are used on high stress components like rod ends, bearing caps, heads etc, becuase when the nut is tightened onto the stud, less force is needed to overcome the friction of the threads, hence more accurate residual stress to hold the pieces together, and a more accuracey when torqueing.
Although for rod ends (on a car) we use a stretch gauge.
Appologies if you alredy know some of that.
All in my opinion of course.

But I did also do a course on torque, in a previous life, when I worked QC and dimensional inspection. Now I'm just a humble mariner...
But we can agree on one thing... after giving it some thought, I'll just use new nuts with some copaslip.
Cheers,
Mick.